1. Field of the Invention
The present invention is directed to expansion joints for gas pipelines and maintenance systems therefor. In particular, the present invention relates to a device for the automatic monitoring, detection, and notification of failure for the control and maintenance of pipeline expansion joints.
2. The Prior Art
It is well known that expansion joints, particularly those involved in gas pipelines, may be subjected to vibration, expansion, contraction, deflection, and bending forces which may eventually lead to failure of the expansion joint.
Typical prior art detection systems for notification of impending failure of an expansion joint require visual inspection of the notification system, which is located in close proximity to the expansion joint. Such notification systems incorporate a sensor that constantly monitors the pressure (or some other characteristic) between two adjacent plies of an expansion joint, such as two adjacent layers of a multiple ply bellows. For example, when a pressure change between the plies of the expansion joint occurs, indicating failure of one (usually an inner one) of the plies, a mechanical pop-up button is actuated and exposed to indicate the at least partial failure of the expansion joint. However, because the pop-up button notification system is in close proximity to the expansion joint, notification of the failure to relevant personnel only occurs when such personnel are inspecting the joint in person. Because such inspections occur over significant intervals of time, the time period between the actual expansion joint's failure, including the subsequent activation of the pop up button, and the actual detection of the failure can be considerable, and total failure of the joint may occur before inspection takes place.
Furthermore, such pop-up button type failure detection and notification systems typically are only activated when the pressure differential reaches and exceeds, for a sustained period of time, a specific value.
It would be desirable to provide an expansion joint monitoring and notification device that provides reliable automatic notification to a remote location of the expansion joint's integrity and thereby eliminates the requirement of direct visual observation and actual proximate physical presence of personnel before a failure is detected.
It would further be desirable to provide a monitoring and notification device that could be able to give notification of the status of a expansion joints integrity by constant or periodic evaluations, enabling for the possibility of predicting the potential and time period before expansion joint failure occurs.
These and other desirable characteristics of the present invention will become apparent in view of the present specification, including the claims, and the drawings.